Amides of n-acyl sarcosines



United States Patent Oflflce AMIDES F N-ACYL SARCOSINES John W. Thompson and James C. Ownby, both of P.(). Box 511, Kingsport, Tenn. 37662 No Drawing. Continuation of application Ser. No. 152,642, Nov. 15, 1961. This application Aug. 2, 1966, Ser. No. 569,754

5 Claims. (Cl. 260-4045) This application is a continuation of Ser. No; 152,642 filed Nov. 15, 1961.

This invention relates to improved mineral oil compositions, more particularly to certain additives which improve thermal stability of hydrocarbon liquids, especially jet engine fuels.

Some jet airplane systems are now designed to employ fuel stored in the plane as a heat sink to absorb heat generated in operation of the aircraft. The fuel may be heated in the tanks of the plane to high temperatures in the magnitude of 400-500" F. before it is ultimately consumed. Some jet fuels are unstable at these high temperatures. They deteriorate to form sludge which may clog fuel lines, filters and heat exchangers and may form harmful deposits in the engine.

A particular object of this invention is to provide jet engine fuels stabilized with certain additives that inhibit sludge formation at elevated temperatures. More generally an object is to provide certain additives for stabilizing liquid hydrocarbon fuels against deterioration at high temperatures. Another object is to provide new compounds useful as thermal stabilizers for hydrocarbon fuels, especially for jet engine fuels. The group of compounds which we have found suitable as additives for stabilizing jet fuels against high-temperature deterioration consists of certain N-acyl sarcosines and certain amide and diamide compounds which may be obtained by condensation of N-acyl sarcosines with certain amines and polyamines.

The N-acyl sarcosines which are effective stabilizers are those having the general formula:

0 CH3 0 H l H amide derivatives are represented by the general formula:

i E i RC-NCH2-CN RV/ wherein R is the same as R defined above, R represents a hydrogen atom or alkyl radical and R" represents an alkyl, alkenyl, or alkylamino alkyl radical. In preferred embodiments, the total number of carbon atoms in R and R" does not exceed 24.

Preferred amines for preparing these derivatives may be primary alkyl amines, secondary dialkyl amines, or dialkyl amino alkyl amines. Examples of some typical amines that may be used for preparing these amide derivatives are methyl amine, dimethylamine, diethylamine, and dimethylaminopropylamine. Mixtures of amines of the type indicated are suitable for this purpose, for instance, a mixture of alkyl amines known as Primene 3,324,155 Patented June 6, 1967 81R. This is essentially a mixture of tertiary alkyl, primary amines in which the amino group is attached to a tertiary carbon atom of an alkyl group containing 18 to 24 carbon atoms per molecule. The condensation product will be a mixture of N-acyl sarcosine amides having the general formula above.

The following example illustrates a typical method for making the monoamide derivative of the invention.

Example 1 Equimolar amounts of N-oleoyl sarcosine and Primene 8l-R were mixed in a reaction flask equipped with a reflux condenser and a Dean-Stark trap. The mixture is then heated and refluxed at a temperature of 190260 F. until no further water collects in the trap. A slightly viscous, light-brown product remains in the flask. An acid number (ASTM D-974) of only 17 indicates the product is essentially the amide condensation product.

Preferred among the stabilizing compounds provided according to this invention are the diamide derivatives of N-acyl sarcosines obtained by condensation of two moles of a N-acyl sarcosine with one mole of a polyalkyleneamine. These diamide derivatives are represented by the general formula:

0 CH3 0 0 CH 0 R--( 3l IOH2iiNH[OH OH NH]niilOHgl l-ii-R wherein R represents an alkyl or alkenyl radical containing not less than 8 nor more than 18 carbon atoms, and

n is 1-4.

Typical of the polyalkyleneamines which may be used as reactants to produce these diamide derivatives are et-hylenediamine, diethylenetriamine, triethylenetetramine, and .tetraethylene pentamine. Following is an example illustrating a preferred method for preparing the diamide derivative.

Example 2 31.8 g. of N-oleoyl sarcosine and 8.4 g. of tetraethylene pentamine (2:1 molar ratio) are mixed in a reaction flask equipped as in Example 1. The mixture is heated and refluxed at 178250 F. until no further water collects in the trap. The residue is a viscous brown liquid. Its acid number is only 1.9, indicating that the residue is essentially the diamide condensation product.

Ability of the stabilizer compounds of the invention to improve thermal stability of jet fuels was tested in the CFR (Cooperative Fuel Research) Fuel Coker.

The test is described in a paper by Crompton et a1. titled, Thermal Stability, a New Frontier for Jet Fuel, and published in the Proceedings of the S. A. E. Summer Meeting in 1955. Instructions for operating the CFR Fuel Coker are in Manual No. 3 of Coordinating Research Council, Inc. Essentially the test is as follows:

Jet fuel is pumped at p.s.i. and at a flow rate of 4-6 pounds per hour through a preheater, thence through a furnace where the fuel passes through a 20 micron, sintered stainless steel filter. In the preheater the fuel is heated to 300-400 F. and in the furnace to 400-500 F. Degradation products are deposited in the preheater and are also trapped on the filter where they eventually cause a pressure drop, which is measured across the filter by a manometer. The test continues until a pressure drop of 25 in. Hg is observed on the manometer, or until expiration of 300 minutes, whichever occurs first. Fuel stability is expressed in goodness units, an empirical function of observed pressure drop and test time. The scale of goodness units ranges from O for immediate clogging to 900 for no observed pressure drop within 300 minutes. At the end of the test the apparatus is disassembled and the preheater parts which were in contact with the fuel are examined for deposited material.

The fuels used to test the additives were ]P4 and JP-S jet fuels. Specifications for these fuels may be found in military specification Mil-P5624 D and in ASTM D 1655-59T. JP-4 fuel is essentially a wide boiling range petroleum fraction composed of about 35 volumes of kerosene and about 65 volumes of aviation gasoline. JP-5 is a kerosene of high flash point (140 F.). Generally, jet fuels can be defined as light, non-viscous, low-flashpoint products with a boiling range of about 140-510 F. These are clearly distinguished from lubricating oils, which have higher viscosity, flash-point, and boiling range.

Fuels designated A, B and C were used in the test. Fuel A was composed of a mixture of several commercially available JP-S fuels, some stable at high temperatures and some unstable. Fuel B was JP-S fuel and Fuel C was a JP-4 fuel.

Table I shows results of CFR Fuel Coker tests of fuels A, B, and C without additives and containing small amounts of some additives typical of the stabilizer of the invention may be added to the fuel simply by mixing the oil and additive together by any suitable means.

Other additives which do not seriously interfere with the sludge inhibiting function of the additives of this invention may also be added to the fuel for other purposes, such as corrosion inhibitors, anti-icing agents, etc.

wherein R is an alkyl or alkenyl radical of about 17 caradditives of the invention. 20 bon atoms, R 1s an alkyl radical of 1-24 carbon atoms,

TABLE I Additive Con- Test Result Fuel Des- Stabilizer Additive centration Goodness Remarks ignation Pounds per Units 1,000 bbl.

'A None None 40 A N-oleoyl sarcosine 2 60 25 838 A Amide product of condensation of N-oleoyl sarcosine with 2 8O Primene 81 R. 5 750 A Amide product of condensation of N-oleoyl sarcosine with 2 100 dimethylamine. A Amide product of condensation of N-oleoyl sareosine with 2 93 dimethylamino-propylamine. 25 710 A Diamide product of condensation of N-oleoyl sarcosine 2 160 with diethylene-triamine. 5 365 A Diamide product of condensation of N-oleoyl sarcosinc 2 708 with tetraethylenepentamine. 5 750 B None None 125 B Diamide product of condensation of N-lauroyl sarcosine 230 with tetraethylenepentanrine. C None None 172 C Diamide product of condensation of N-oleoyl sarcosine 1.5 762 Noticed considerable with tetraethylenepentamine. reduction of deposit in preheater.

In the tests reported in Table I, for testing Fuel A, the preheater temperature was maintained at 400 F. and the temperature at the filter was 500 F. Fuels B and C were tested at preheater temperature of 300 F. and filter temperature of 400 F. The fuel fiow rate for testing Fuel A ws 6 lb./hr. and for testing Fuels B and C" was 4 lb./hr.

The concentration of additive necessary in the fuel to obtain the desired stability will depend upon the initial stability of the fuel being treated as well as upon the particular selected additive. In most cases a proportion somewhere between one lb. and 100 lbs. of stabilizer additive per 1000 bbl. of fuel will serve the purpose, but the optimum concentration will have to be determined for the individual case.

Selection of a particular stabilizer additive from the group provided by the invention will be largely an economic matter, depending upon relative costs of the compounds available and the amount of each required to achieve the desired degree of stabilization. As indicated by the data in Table 1, different concentrations of the different stabilizers may be required to produce the same degree of thermal stability in a fuel. Smaller quantities of the diamide derivative of polyalkylamines are required to produce excellent stability. The N-oleoyl sarcosine derivatives are also preferred for the same reason.

For improving thermal stability of jet fuel and similar hydrocarbon fuels, any of the additives within the scope and R" is an alkyl, alkenyl or alkylaminoalkyl radical or up to 24 carbon atoms.

2. The compound of claim 1 in which 0 ll n-c is oleoyl and R and R are methyl.

3. The compound of claim 1 in which 0 ll RC- is olcoyl, R is propyl and R is dimethylamino.

4. A compound having the formula:

a) $113 (1) CH3 O RCN-CHzC-NH[(CI'I NII].,C-CIIz-I I gR wherein R represents a radical selected from the group consisting of alkyl and alkenyl radicals which contain 8-l8 carbon atoms and n is 14.

5. The compound of claim 4 in which is oleoyl and n is 2 to 4.

No references cited.

CHARLES B. PARKER, Primary Examiner.

ANTON H. SUTTO, Assistant Examiner.

UNITED STATES PATENT ()FFICE CERTIFICATE OF CORRECTION Patent No. 3,324 ,155 June 6 1967 John W. Thompson et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the heading to the printed specification, lines 3 and 4, for "John W.. Thompson and James C. Ownby, both of P. O. Box 511, Kingsport, Tenn. 37662" read John W. Thompson and James C. Ownby, both of Kingsport Tenn. assignors to Eastman Kodak Company, Rochester, N. Y. a corporation of New Jersey Signed and sealed this 17th day of December 1968.

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer 

1. A COMPOUND HAVING THE FORMULA: 